Platform lever mechanism.



F. H. BUGKINGHAM.

PLATFORM LEVER MECHANISM.

APPLIOATION FILED NOV.12, 1908.

967,880. Patented Aug. 23, 1910.

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in N 9 m 2 ii 'WM' l 1 27 as 65 anueul'o'a MEQW F. E. BUUKINGHAM. PLATFORM LEVER MEGHANISM.

APELIOATION FILED NOV. 12, 1908.

Patented Aug. 23, 1916.

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, posed to change their UNITED STATES PATENT OFFICE.

FREMONT H. BUCKENGHAM, DETROIT, MICHIGAN, ASSIGNOR TO THE STANDARD COMPUTING-$011111? COMPFANY, OF DETROIT, MIOHIQAN.

PLATFORM LEVER MECHANISM.

Specification of Letterslatent.

Application filed November 12, 1908.

Patented Au es, i910. SerialNo. 462,217.

To all whom it may concern:

Be 1t known that I, Fnnnon'r H. BUCK- a resident of Jletroit, in the county of llaync and Stat oflvhclngan, have invented a new and useful Platform Lever Mechanism, of which the following is a specific-a.-

tion.

This invention relates to weighing-scales leverv and more particularly to such levers as are specially adapted for spring-balance scales wherein a coiled sn'ing is=e1nployed to resist the movement of the levers, and an.

indicator is actuated by said movement. In order that the indicator may be given the desired actuation it is necessary that the platform lever to which the indicating mechanism is connected shall have an extended movement, and it is the object of this invention to so construct and arrange the platform lever mechanism that it shall have absolute freedom of movement.

My invention consists in the combination of two levers, a platform, and links all so arranged and constructed that the downward pressure exerted by a load on any part of the platform will be resolved into vertical moments with reference to one of the lovers, irrespective of the angular position of either lever.

To this end the construction embodying this invention consists in the construction and arrangement substantially as shown and particularly pointed out in the claims, reference being had to the accompanying drawings in which Figure 1 is a vertical section of a scale embodying the invention and showing the platform levers in side elevation. Fig. 2 is a central vertical section through the base of the scale and through the platform levers supported thereon. Fig. 3 is a transverse vertical section on the line of Fig. 2. Fig. l is a plan view of the levers detached; and Fig. 5 is a diagram showing the movement of the platform lever mechanism.

In the usual beam scale, the poise and weights on the tare beam are for the purpose of keeping the levers and beams balanced. The platform levers are not supthe 80th day of April, 1908,

angular relation to' each other or to the remainder of the mechanism. The question to be solved is;what counter-stress is necessary to. prevent the weight from moving the platform or scoop.

In platform-lever spring-scales the dis tance the platform moves againstthe force of a spring is to be measured and to do this, the platform and the levers that support it must move with absolute freedom. The pressure exerted by the weight must be vertically applied to the main lever, whether directly or through auxiliary levers, irrespective of the angle through which the levers or platform travel. It is also necessary that none of the force of the weight be expended in overcoming friction or in side thrusts on bearings. It is therefore necessary that all parts move with perfect freedom of movement and that there be no twisting or binding at any of the bearings.

As shown in the drawings, 1 is a suitable base upon the rear end of which is erected a vertical hollow pedestal or column-2 to the upper end of which is secured a horizontally extending cylindrical casing 3 inclosing and supporting a suitable rotary indicating drum 4. This drum is secured to a supporting shaft- 5 which is provided with a pinion 6 adapted to engage a rack-bar 7 upon the upper end of a vertically extending rod 8, which rod extends downward within the hollow column and is attached at its lower end to a suitable head 9. One or more coiled springs 10 are attached at their lower ends to the head 9, and at their upper ends are secured to a suitable supportingbar 11. A draft-rod 12 is attached at its upper end to the head 9 and at its lower end it is provided with a yoke 13 having suitable bearings to receive the knife-edge pivots 14 carried by the main lever 15 of the platform lever mechanism. The extended end of the lever 15 is forked and projects into the lower end of the column 2 at each side of a. suitable dash-pot 16.

All of the,foregoing parts are constructed and arrange to operate substantially as shown and described in an application filed Serial Number 130,205, and forms no part of this invention.

The main lever 15 of the platform lever chanism is provided at its rearwardly exded end with the knife-edge pivots 1s and is pivotally supported st its extreme forward end upon supportingposts 17 on the base 1 by the knife-edge pivots 18 restll'lg on suitable bearingblocks on said posts. lmeruiediate its end this lever is provided with hniteedgc pivots 19 toengage suitable bearings carried by the lugs 20 which pend downward from. the platform upon which he platform :22 iin :uixiliary lever 23 is provided at its for ward end with knife; lge pivots 2st to ensuitable bearing-blocks carried by the in 25 extending downward from the forward side of the platform frame.

it link 26 is givotally connected at its lower end to the base 1 being provided with a knife-edge pivot to engage a suitable block 27 secured. to the base, and at its upper end said link is provided with a bearingblock 28 adapted to be engaged by a knifeedge pivot 29 carried by the rear end of the lever Half-way between the pivots 18 and 19 the main lever 15 is provided with the knife-edge pivots 30, from which pivots hang the loops or links 81. Supported by these loops or links, and extending across and between the same, a bar provided with projecting knife edge pivots 33 to enthe loops or links. Secured upon this bar adjacent to its pivots are suitable bearing-blocks adapted to be engaged by knifeedge pivots 3-2: on the auxiliary levers 23 to 817)}301h said lever intermediate its ends. ["ne auxiliary lever is thus supported and carried by the main lever tl'irough the medium or the downwardly hanging loops 231 which permit a longitudii'ial movement of the auxiliarydever relative to said main lever. The pivots 34. are halt' way between the oivots 2i and .29. A. distance rod is pivotally attached at one end to the link 26 lisli way between the bearings 27 and thereof, and at its opposite end is pivotally attached to the bar 32 in any suitable. manner by providing a hole in the bar to receive a plug 36 which provided with aslct in which the end of the distance-rod 50 maybe pivotally secured.

W Referring to the diagram, Fig. 5, it will be seen that when the platform is loaded the bearings 15 and 30 of the lever 15 move in a cs having the bearing ill for a center. he 19 to the will also move in the same are as These arcs may be resolved err" vertical and liorircoi'ital componlink 2b is connected to the lever l orizontal. movement of the free n l; will be practically that of the andv 11s the point Ill) ,vxeen 18 and 15), the horizontal 'components of the movement of the bearing 30 will be one half those of the bearing 8% but in the same directions. When the levers are depressed by a load, the bearings ill will move rearwardly, passing the line of the bearings 30. The rod being connected to the middle point of the link 26, the bearings will move rearwardly just one half as fast as the bearings 3%, that is, at the same rate as the bearings 30. in other words, the line of the bearings will always be vertically'under the line of the bearings 30. By this construction, the effective lines of the bearings 30 and 3% may be at the same level without binding or diagonal thrusts. It will also be noticed that the parts are so proportioned tiat the rod and the lever 23 are parallel so that the link 32 will always be parallel to the link 26. This secures perfect movement of the levers on their knife-edge bearings. The pressure of any load on the platform will be transmitted to the lever 15 directly at 19 or indirectly at 30, butwill always be in vertical lines. Considering a concrete case. The dis tances 1930 and 3018, are three inches, the vertical height between 18 and 19 runs from oneinch above to one inch below horizontal. The length of 32 is one inch and of 26 is two inches. The vertical angle of 15 will vary from 91} degrees above to the same amount below a horizontal line. The distances 2l3-fl and 34.28 are equal. The horizontal distance traveled by 19 when moving to the horizontal plane of 18 will therefore be the versed sine of this angle which is .OSl inch. The bearing 32 is one twelfth of an inch in front of the bearing 30 when the platform is unloaded and the same distance to the rear when the full load is on the scale. he distance .Otll inch is also one half of the horizontal movement of the bearing 28. This gives the link a n'iovenient of degrees each way from the vertical. The vertical component of this movement is .0017 inch and of the point 34- is just one half this amount. The movements below the horizontal line of the pivot 18 are the same as above. The bearing 24 is therefore the pivot, when the vertical n'iovemenls of 2S and 34: are considered, which explains why the platform will always remain level throughout its nioveincnt. The distance between the pivots 28 and 2-1 will always have the same proportion to the distance between pivots and ll, as the distance between the pivots if) and 18 bears to the distance between the pivots $0 and 1.8. 'iliere is no absolute necessity for the levers l5 and "2 3 having their pivots ill) and ill half way between adjacent pivots, it merely happens to be desirable from the manul aclurcrs slai'ldpoint. The point ol connection of the rod to the link 243 w ll also hold to the same rule of proportion.

Having now explained my improvements, What I claim my invention and desire to secure by Letters Patent is 1. In a platform scale lever mechanism, the combination of a main lever, a fixed pivot for one end of the same, an indicator connected to the other end of the main lever, an auxiliary lever, a platform supported by said levers, a swinging pivot for one end of the auxiliary lever, links connecting intermediate points of the levers, and means extending between said links and swinging pivot for causing a plurality of said links to han vertically under the point of connection with the main lever.

;2. In a platforni scale lever mechanism, the combination of a base, a platform, a pair of levers supporting the platform, a link connecting one lever to the base. a second link coime'ctinpsaid levers at points intermediate their ends, and meansto hold said links parallel to each other.

3. In a platform-scale lever mechanism, the combination of a main lever having knife-edge pivots at both ends and intermediate its ends, a base, a support for the pivots at one end of the main lever mounted on the base, an indicator connected to the pivots at the opposite end of the lever, an auxiliary lever provided with knife-edge pivots at both ends and intermediate its ends, a weight receiver resting on pivots intermediate the ends of the main lever and at one end of the auxiliary lover, a knife edge pivot mounted on the base, a link engaging the same and a pivot at the opposite end of the auxiliary lever, connecting links between pivots on the levers, and a controlling device betweenthe links.

4. In a scale lever mcchanismdthe combination of a Jair of levers, pivots for one end of each ever, connecting links between said levers, and a weight receiver engi 'ing one lever intermediate its ends and the, lit-her lever at one end.

5. In a platform-scale lever mechanism, the combination of a main lever pivotally supported at one end and adapted to be connected to the indicating means at its opposite end, an auxiliary lever, a platform supported by the main lever at a point intermediate the ends of said lever, and by one end of said auxiliary lever, and links connecting said lovers to support the auxiliary lever upon the main lever and permit the auxiliary lever to move with the platform and relatively to the main lever.

6. In a platform-scale lever mechanism, the combination of a mainlever 'pivotally supported at one end, an auxiliary lever, a platform supported by the main lever and one end of the auxiliary lever, means connecting said levers and permitting a relative longitudinal movement, and retaining means for the opposite end of said. auxiliary lever adapted to permit said longitudinal movement thereof.

7. In a platform-scale lever mechanism, the combination of a main lever pivotally supported at one end. an auxiliary lover, a platform supported by the main lever and by one end of said auxiliary lever, retaining means for the oppcsite end of said auxiliary lever adapted to permit said lever to move longitlulinally. and means for supporting the auxiliary lever upon the main lever and permitting a relative movement between the said levers.

8. In a platform scale lever "-mechai'iism, the combination of a main lever pivotally supported at one end, an auxiliary lever, a platform supported by the main lever and by'one end of said auxiliary lever, a link pivotally attached to the opposite end 0*t' said auxiliary lever and adapted to swing to permit a relative movement between the levers, and means for supporting the auxiliary lever from the main lever and permitting a relative movement between said levers.

In a. platform-scale lever mechanism, the (IOHlbll'ltllflOll of a main lever pivotally supported at one end and adapted to be connected to indicating means at its opposite end, an auxiliary lever, a platform supported by the main lever at a point, intermediate the ends of said lever, links pivotally connected to the main lever and extending downward a cross bar to support the auxiliary lever and pivoted in said links so as to permit a relative movement between said levers, and means for maintaining said links in a vertical plane.

10. In a platform-scale lever mechanism, the combination of a main lever pivotally supported at one end, an auxiliary lever, a weight receiver supported by the main lever and by one end of the auxiliary lever, a movable'pivot for the opposite end of said auxiliary lever, and loops to support the auxiliary lever from the main lever.

11. In a platform-scale lever mechanism, the combination of a main lever pivotally Isupported at one end, an auxiliary lever, a platform supported by the main lever and by one end oflsaid auxiliary-lever, means pivotally attached to afixed support and pivotally attached to the opposite end of said auxiliary lever, and loops carried by the main lever and supporting at their lower ends the auxiliary lever intermediate its ends.

12.- In a platform-scale lever mechanism, the combination of a main lever pivotally supported at one end, an auxiliary lever, a platform supported by the main lever and by one end of said auxiliary lever, a pivoted connection between saidauxiliary lever and a fixed support for permitting the longitudinal movement of said lever, means pivotally attached to the main lever and hanging downward therefrom, a cross bar for attaching the auxiliary leverto the lower end of said hanging means and permitting a longitudinal movement of said lever relative to said hanging means and a rod extending between the pivoted connection and the cross bar.

13. In a platform-scale lever mechanism,

the combination of a main lever pivotally.

supported at one end and adapted to be con nected to indicating means at its opposite end, an auxiliary lever, a platform supported by the main lever at a point intermediate the ends of said lever and by one end of said auxiliarylever, means pivotally attached to the opposite end of sald auxiliary lever to pivotally hold the same and permit a longitudinal movement of saidlever, means pivotally attached at its upper end to the main lever and hanging downward therefrom, a cross bar pivotally supporting the auxiliary lever intermediate its ends and pivotally carried by the lower end or" the downwardly hanging means and means connecting the cross bar and the pivotal connection at the end of the auxiliary lever. c

14:. In a platform-scale lever mechanism,

' the combination of a main lever pivotally supported at one end and adapted to be connected to indicating means at its opposite end, an auxiliary lever, a platform supat its lower end the lower end of said loop to turn relatively thereto and a rod connecting the link and bar.

15. In a platform-scale lever mechanism, the combination of a main lever pivotally supported at one end and adapted to be connected to indicating means at its opposite end, an auxiliary lover, a platform supported by the main lever at a point intermedinle the ends of said lever and by one end of said auxiliary lever, 11 pivoted llnk pivotally attached to the opposite end of said auxiliary lever, dmvnwardly hanging means carried by the main lever, means for Supporting the auxiliary lever pivotally attached to the lower end of said downwardly hanging means, and a connector in engagement with said pivoted link and the supporting device for the auxiliary lovely-ton maintaining the downwardly hanging means in a vertical plane as the main lever site end, an auxiliary lever, a platform sup ported by the main lever at a point intermediate the ends of said lever and by one end of said auxiliary lever, a loop pivotally carried by the main lever, means pivotally supported by the lower end of said loop to turn thereon and supporting said auxiliary lever at a distance from its pivotal support on said loop'equal to the distance from said point of support to the pivot of said loop on the auxiliary lever, and means for maintaining said loop in a vertical plane.

17. In a platform-scale lever mechanism, the combination of a main lever pivotally supported at one end and adapted to be connected to indicating means at its opposite end, an auxiliary lever, a platform supported by the main lever at a point intermediate the ends of said lever and by one end of said auxiliary lever, a pivoted link pivotally attached at its upper end to the opposite end 18. In a platform-scale lever mechanism,

the combination of a main lever pivotally supported at one end and adapted to be connected to indicating means at its opposite end,-an auxiliary lover, a platform supported by the main lever at a point intermediate the ends of said lever and by one end of saidauxiliary lever, a link pivoted to a fixed support at its lower end and to the opposite; s

end of said auxiliary lever at its upper: end,

loops carried by the main lever and hanging downward therefrom, a cross-barc'arried'by support the auxiliary lever and to turn upon said loops when the auxiliary lever is'inoved longitudinally relative to the main lever, and a distance-rod connected to said link at one end and to said cross-bar; at its opposite end.

the lower ends of said loops and adapted to 19. In a platform-scale;lever mechanism, the combination of; a'mam' 'lever;.p1v0tally supported, at one end and adapted tojbe connected to indicating means at its oppo- 5 site endpan aux liary.,lever a platform sup; ported by the naln lever at-a polntl nter mediatelhe ends of. saidllever landby one bud; of said. auxiliary}: lever,.,alink pivotally 1125 attached to a' 'fixe'd support at enema and :tolhe ,o 'ipositefend of said auxiliary lever at itsouierend, loops pivotally carried bv the s eezgeeo main lever, e cross-bar having bearings at its ends engaging the lower ends of said loops and provided with bearings at upper side to support the auxiliary lever in tei'mecliate the ends of said lever, and e (listence-rod pivotally attached to the cross-bar and to the said link intermediate the ends thereof.

20. In a platform-scale lever mechanism, the combination of a base, a platform, tvvo levers supporting th esarne, a fined pivot for one lever a swin ino' connection between the base and the other lever, a swinging connection between the levers, and means to hold these connections parallel to each ot er.

21 In platform-scale lever mechanism, the combination of a pair of levers, a plat form supportecl thereby, said platform conneetecl to the free end one lever and lievends adapted at tween the ends of the other, and a flexible connection including links between the le vers.

22. In a platform-scale lever mechanism, the combination of a pair of levers, a portion of one extending above the other, a platform connected to the free end; of one lever and intei'n'ieiliete the ends to the other, said levers having pivots intermediate theii times to be in the same ver tical plane, and zneens to connect sei l pivots.

In testimony whereof I have signed this specification inthe oresenee of two shseribing Witnesses. I

Witnesses I G. .Rnmon, Gnonen *Csmn'roN 

